$ { {-4} \times \left[\begin{array}{rrr}{2} & {4} & {1} \\ {4} & {3} & {0}\end{array}\right] = {?} } $
Answer: To multiply a matrix by a number, multiply each item of the matrix by the number. ${\left[\begin{array}{rrr}{-4}\times{2} & {-4}\times{4} & {-4}\times{1} \\ {-4}\times{4} & {-4}\times{3} & {-4}\times{0}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rrr}{-8} & {-16} & {-4} \\ {-16} & {-12} & {0}\end{array}\right]}$